1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a driving method of the same.
2. Discussion of the Related Art
With rapid development of information technologies, display devices processing and displaying a large amount of information have been rapidly developed. Recently, flat panel display (FPD) devices such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device and an organic light emitting diode (OLED) device have been suggested.
Among the various FPD devices, the LCD device has been widely used for its superiorities of small size, light-weight, thin profile and low power consumption. Meanwhile, active matrix type liquid crystal display devices, which include pixels arranged in a matrix form and thin film transistors to control on/off the respective pixels, have been widely used because of their high resolution, color rendering capability and superiority in displaying moving images.
Recently, in an LCD device for mobile devices, an image data of a black level of a gray scale has been widely used, and its displaying time has been increased. Thus, there is a problem of an afterimage at the black level in addition to afterimages at middle levels or low levels.
The afterimage at the black level will be explained with reference to Table 1. Table 1 shows a driving voltage at each level of a gray scale in a normally black mode.
In Table 1, the driving voltage of the black level Gray0, which is a zeroth gray level, is 0.222V, and this is for a gray scale inversion. More particularly, brightness at the levels of the gray scale should be gradually increased. At this time, the driving voltage of the black level Gray0 is lower than a voltage at which a gray inversion occurs, and the driving voltage of a first gray level Gray1 is higher than the voltage at which the gray inversion occurs. The driving voltages of second and third gray levels Gray2 and Gray3 are gradually increased. Here, the gray inversion may occur at about 0.3V, and the driving voltage of the first gray level Gray1 may be about 0.4V.
TABLE 1Graydriving voltage (V)00.22210.36720.42130.47640.51250.55560.59970.64280.68690.729100.791
However, as stated above, when the driving voltage of the black level Gray0 is about 0.2V and the image data of the black level Gray0 is displayed for a long time, liquid crystal is affected by 0.2V. Therefore, the image data of the black level displayed at a current frame remains at a next frame, and there is an afterimage.